Such a type of polypectomy snare has already been known in DE 7835595. The known polypectomy snare or diathermy snare is made up of a tensile wire. The tensile wire enters a loop similar to a semicircle at a front end thereof and comes to an end there. The loop has a peak. The tensile wire is easily guided in a bushing and a corresponding pipe-shaped stopper member disposed at an end of the bushing. One of two legs of the loop is fixedly connected to the tensile wire. As a result, the loop can be displaced from a storage position at which the loop is placed in the bushing in an expanded state to a use position at which the loop is located in front of an end of the bushing by the tensile wire. The other leg of the loop which is located in the bushing is connected to a stopper moving toward a corresponding stopper in the process of extracting the loop out of the bushing. As a result, when the other leg of the loop continues to move, the loop is expanded, in a semicircular shape.
A high-frequency resection apparatus capable of supplying electric current to a snare as described above is known in DE 2951060. Here, the snare acts as an electrode. The apparatus formed in this way is used to resect abdominal tissue such as a tumor using high-frequency current according to a system for resecting a region that is located in an abdominal cavity, particularly in an intestine, and that has a tumor, for instance one or more polyps. In the region, the high-frequency current can flow between an electrode, which is intended for resection and is formed by a snare-shaped conductive wire guided into the cavity, and an outer electrode, which is fixed to skin of a patient and is disposed apart from the resection electrode.
In the event of resection, a surgeon should, typically place a loop inserted into the abdominal cavity on the polyp using an endoscope.
This conventional polypectomy snare is rotated as a whole in order to insert the loop to a spot where the polyp to be removed has grown along with an endoscope and rotate the direction of the loop in the direction in which the polyp has grown, thereby facilitating the insertion of the polyp into the loop. Since the entire polypectomy snare is rotated, there is a problem in that the surgeon cannot smoothly rotate the loop in a desired direction and a burden imposed on a wrist is increased.
For this reason, a medical snare for removing the polyp, which can easily rotate an expansion direction of the loop in the direction in which the polyp has grown and that allows the polyp to be smoothly inserted into the loop to reduce time required for the surgical procedure and to easily perform the surgical procedure, is urgently required.